Fix conflict of dirname GuardDuty to guardduty. fix #1753

[hori-ryota]

For changes to files under the /model/ folder, and manual edits to autogenerated code (e.g. /service/s3/api.go) please create an Issue instead of a PR for those type of changes.

If there is an existing bug or feature this PR is answers please reference it here.

fix directory name models/apis/guardduty conflict · Issue #1753 · aws/aws-sdk-go

[hori-ryota]

build failed but I didn't touch s3manager 😇

--- FAIL: TestUploadUnexpectedEOF (0.04s)
	upload_test.go:824: Expected "UploadPart", but received "AbortMultipartUpload"
panic: interface conversion: interface is nil, not io.Reader [recovered]
	panic: interface conversion: interface is nil, not io.Reader
goroutine 252 [running]:
testing.tRunner.func1(0xc420096a50)
	/home/travis/.gimme/versions/go1.9.2.linux.amd64/src/testing/testing.go:711 +0x5d9
panic(0xb91040, 0xc420170680)
	/home/travis/.gimme/versions/go1.9.2.linux.amd64/src/runtime/panic.go:491 +0x2a2
github.com/aws/aws-sdk-go/service/s3/s3manager_test.buflen(0x0, 0x0, 0xc27c09)
	/home/travis/gopath/src/github.com/aws/aws-sdk-go/service/s3/s3manager/upload_test.go:96 +0x4f
github.com/aws/aws-sdk-go/service/s3/s3manager_test.TestUploadUnexpectedEOF(0xc420096a50)
	/home/travis/gopath/src/github.com/aws/aws-sdk-go/service/s3/s3manager/upload_test.go:832 +0xa92
testing.tRunner(0xc420096a50, 0xc459b8)
	/home/travis/.gimme/versions/go1.9.2.linux.amd64/src/testing/testing.go:746 +0x16d
created by testing.(*T).Run
	/home/travis/.gimme/versions/go1.9.2.linux.amd64/src/testing/testing.go:789 +0x569
FAIL	github.com/aws/aws-sdk-go/service/s3/s3manager	12.485s

[xibz]

Thanks @hori-ryota! I'll go ahead and merge this once I take a look at the travis failure.